Among the other unpleasant aspects of having the disorder diabetes mellitus is the need to frequently test one's blood glucose concentration. With current technology a diabetic patient must prick his own fingertip or other body part with a lancet in order to withdraw blood from the wound. The fingertip is preferred because of the great number of capillaries located there.
The breach created through the skin by the lancet must be wide enough to permit blood to flow through. Human epidermis around the fingertips is on the order of 1–3 millimeters thick. Also, similar to other flexible, sheet like materials, skin tends to close up on itself if breached. Accordingly the lancet used must create a breach that is wide enough to not be closed by the natural action of the skin.
Moreover, the task of sampling one's own blood has generally required that a flat surface be present for the patient to arrange various test articles including a test strip, a lancet and a cotton ball with alcohol, for sterilizing the wound. As a result, it has heretofore been impossible for a diabetic patient to measure his blood glucose level in a public place without drawing attention to himself. Interviews with diabetic patients indicate that the workplace, where there is frequently a definite lack of privacy and where maintaining the secrecy of personal information may be greatly desired, presents particular difficulties.
A number of disclosures are aimed at easing this requirement by providing an integrated unit having a number of lancets and associated test articles (such as a test strip or a sensing cavity to be filled with blood drawn out from the body) and in which both lancet and test article are contemporaneously moved into test position. These devices tend to use chemical test strips, rendering them rather bulky and typically requiring the user to place a test strip in place before use.
In addition, a number of disclosures are directed at an implantable or insertable sensor, for continuous glucose monitoring. Although this technology appears to bear promise it is desirable to have additional options for the diabetic patient. For example, a method of quickly and easily making an occasional determination of blood glucose concentration would be helpful for patients not wishing to wear a glucose monitor.
Ease of use is not only an important consideration from the perspective of patient comfort, but also from the perspective of patient health. The easier it is for a patient to take his blood glucose level reading, the more frequently he is likely to do so. In turn, with more frequent measurements, the patient is likely to do a better job at regulating his glucose level and thereby avoiding chronic complications in which body tissue is damaged by toxic glucose levels or acute complications in which the patient is in danger of entering a state of hypoglycemic shock. Moreover, by more frequently measuring his or her glucose levels, the patient will likely form a better understanding of his body's response to the consumption of varying types of food and of varying degrees of physical exertion. The better the patient understands his body's response characteristics the better he will be able to tailor his eating, exercise and insulin injection or ingestion regime.